In many applications, such as telerobotics, a handheld device is used to control many different functions of electromechanical apparatus. A hand-held control device (box or handgrip) is often provided with push buttons and/or switches to be actuated by an operator. For example, moving a toggle switch or moving a push button switch, and the like, controls special functions of a robot such as to grasp or release, lock or release current position, and emergency stop or resume. Thus, the handheld controller has a multiplicity of control functions which are transmitted to the controlled apparatus over a cable. Because of space, weight, and other constraints, it is often desirable to reduce the number of conductors in this cable to a minimum.